NNLOPS accurate associated HW production

We present a next-to-next-to-leading order accurate description of associated HW production consistently matched to a parton shower. The method is based on reweighting events obtained with the HW plus one jet NLO accurate calculation implemented in POWHEG, extended with the MiNLO procedure, to reproduce NNLO accurate Born distributions. Since the Born kinematics is more complex than the cases treated before, we use a parametrization of the Collins-Soper angles to reduce the number of variables required for the reweighting. We present phenomenological results at 13 TeV, with cuts suggested by the Higgs Cross Section Working Group.Comment: Minor changes, plots updated, matches the version published in JHE

Analytic double-soft integrated subtraction terms for two massive emitters in a back-to-back kinematics

We consider the double-soft limit of QCD amplitudes with two massive quarks in a back-to-back kinematics accompanied by two soft partons. We integrate analytically the respective double-soft eikonal functions over the phase space of the two soft partons. Within the context of the nested soft-collinear subtraction scheme, our results may serve as one of the integrated subtraction terms needed for the analytic and fully-differential description of next-to-next-to-leading order (NNLO) QCD corrections to colour-singlet decay into massive partons or to heavy-quark pair production

Momentum-space resummation for transverse observables and the Higgs p⊥p_\perp at N3^3LL+NNLO

We present an approach to the momentum-space resummation of global, recursive infrared and collinear safe observables featuring kinematic zeros away from the Sudakov limit. In the hadro-production of a generic colour singlet, we consider the family of inclusive observables which do not depend on the rapidity of the radiation, prime examples being the transverse momentum of the singlet, and $\phi^*$ in Drell-Yan pair production. We derive a resummation formula valid up to next-to-next-to-next-to-leading-logaritmic accuracy for the considered observables. This formula reduces exactly to the customary resummation performed in impact-parameter space in the known cases, and it also predicts the correct power-behaved scaling of the cross section in the limit of small value of the observable. We show how this formalism is efficiently implemented by means of Monte Carlo techniques in a fully exclusive generator that allows one to apply arbitrary cuts on the Born variables for any colour singlet, as well as to automatically match the resummed results to fixed-order calculations. As a phenomenological application, we present state-of-the-art predictions for the Higgs-boson transverse-momentum spectrum at the LHC at next-to-next-to-next-to-leading-logarithmic accuracy matched to fixed next-to-next-to-leading order.Comment: Journal versio

On the interference of ggHggH and ccˉHc\bar{c}H Higgs production mechanisms and the determination of charm Yukawa coupling at the LHC

Higgs boson production in association with a charm-quark jet proceeds through two different mechanisms - one that involves the charm Yukawa coupling and the other that involves direct Higgs coupling to gluons. The interference of the two contributions requires a helicity flip and, therefore, cannot be computed with massless charm quarks. In this paper, we consider QCD corrections to the interference contribution starting from charm-gluon collisions with massive charm quarks and taking the massless limit, $m_c \to 0$. The behavior of QCD cross sections in that limit differs from expectations based on the canonical QCD factorization. This implies that QCD corrections to the interference term necessarily involve logarithms of the ratio $M_H/m_c$ whose resummation is currently unknown. Although the explicit next-to-leading order QCD computation does confirm the presence of up to two powers of $\ln(M_H/m_c)$ in the interference contribution, their overall impact on the magnitude of QCD corrections to the interference turns out to be moderate due to a cancellation between double and single logarithmic terms.Comment: 28 pages, 4 figure

Bottom quark mass effects in associated WHWH production with H→bbˉH \to b\bar{b} decay through NNLO QCD

We present a computation of NNLO QCD corrections to the production of a Higgs boson in association with a $W$ boson at the LHC followed by the decay of the Higgs boson to a $b\bar{b}$ pair. At variance with previous NNLO QCD studies of the same process, we treat $b$ quarks as massive. An important advantage of working with massive $b$ quarks is that it makes the use of flavor jet algorithms unnecessary and allows us to employ conventional jet algorithms to define $b$ jets. We compare NNLO QCD descriptions of the associated $WH(b\bar{b})$ production with massive and massless $b$ quarks and also contrast them with the results provided by parton showers. We find ${\cal O}(5\%)$ differences in fiducial cross sections computed with massless and massive $b$ quarks. We also observe that much larger differences between massless and massive results, as well as between fixed-order and parton-shower results, can arise in selected kinematic distributions.Comment: 30 pages, 9 figure